I also read the backtobangladesh blog, its quite nicely written. However on a related note, its not uncommon for people in their 50's, who have spent 20+ years in the USA to actually overlook many of the inconveniences that someone in their 30's wouldnt.

They get tired of living abroad, and come back to Bangladesh after having secured their finances and as such are free to enjoy living in BD and not worry about things that would make a 30 yr old mad (kids schooling, rising costs etc,)

Again, that said, family is a very important reason, and while I dont know your situation, if one parent , God forbid, has some chronic illness, it does tend to make more sense to go back so that once can be close to him/her. No money in the world can compensate for a parent.....